)DeHl 



/J 



A TREATISE 






P T A T 



AN ESSAY 



TO SHOW 



THE CAUSE OF THE DISEASE 



AND TO SUGGEST 



ITS REMEDY. 



By WM. J. A. BRADFORD. 



^^;(OFco 



0/3 BOSTON: 
PRINTED FOR THE AUTHOR, 

-^>ei' t BY J. B. CHISHOLM, NO. 5 WATER STREET. 

1852. 



TO THE 

FARMERS OF THE UNITED STATES, 

ENGAGED IN THE 

MOST USEFUL, 

MOST HONORABLE, 

MOST INDEPENDENT AND HAPPY 

OF ALL THE PURSUITS OF MAN, 

4)m ftiii '^k^m m lUspntfullti Sn5rrilir&; 

IBT IHE HOPE THEY MAY PEOVE TO THEIR BENEFIT 
AND TO GENERAL ADVANTAGE, 

By THE Author. 






TREATISE ON THE POTATO. 



HISTORY OF THE USE AND CULTIVATION OP' THE POTATO. 

The potato is so associated in our minds, in this countiy^ 
with the things that are agreeable to the palate and good 
for food, is so regular an accompaniment of all provision 
for the inner man, whether it be the most humble meal 
procured for the urgent cravings- of hunger, or the most 
costly and sumptuous banquet designed to gratify extrava- 
gant gourmandism or splendid luxury ; whether it be for 
fast or feast ; that it is difficult for us to separate it, even 
in fancy, from the list of things necessary to subsistence, 
or to conceive of the time when it was not in use, or of 
the possibility that we can or must, ourselves, in future 
do without it. There is, at present, no vegetable candi- 
date for our favor, and for general popularity, that appears 
qualified to succeed it at the board. How far the psoralia 
esculenta, or wild potato of the western prairie ; or the 
helianthus tuberosus, or Jerusalem artichoke, may fill the 
important void to be made at the table if the potato should 
actually leave us, is not certain. 

The potato has been in use among the civilized part of 
mankind from a date about coeval with the settlement of 
this country. It was a scion of uncivilized Peru in the days 



4 HISTORY OF THE USE AND 

of the Incas, and of barbarous Virginia before the time of 
Pocahontas. Sir Walter Raleigh, on a voyage to Vii-ginia 
in 1586, became sensible of its merits and amiable qualities, 
and fancied it also to have some others, which it does not 
appear, on better acquaintance, to possess, and he exported 
it thence to England and Ireland. This is related on the 
authority of Sir Joseph Banks, and it is said that the 
plants imported by Raleigh were first cultivated at his 
farm in Youghal, in Ireland. Robert Southwell, President 
of the Agricultural Society, stated to that body, in 1693, 
that his father received them from Sir Walter Raleigh, and 
first introduced them into Ireland. This is probably a 
mistake, as they must have been in Ireland before his day. 
In a description of them by Thomas Heriot, they are called 
opanawk. " These roots," he says, " are round, some as 
large as a walnut, others much larger. They grow in 
dam]3 soil, many hanging together, as if fixed on roj)es. 
They are good food, either boiled or roasted." Mr. Heriot 
apparently refers to some of the product raised m England, 
not to the original stock brought from Virginia. They 
had probably increased somewhat in size in England, as 
the usual size of the potato growing in its natural state, 
in Virginia or Peru, is elsewhere described as less, being 
about the size of a nutmeg. The size of the potato, with 
us, in the first year from the seed, will not exceed that 
measure, unless the vine be transplanted. The size of the 
tuber as commonly sold in our markets, the produce of 
careful husbandry or gardening, is acquired by cultivation. 
Gerarde describes the potato as the Virginia potato, and 
says that he received the roots from Virginia. This ac- 
count is published by him in his Herbal, in 1597. He 
recommends them to be eaten as a delicacy, not as com- 
mon food. The potato was known in Spain before it was 
in England, and was probably brought there by the dis- 



CULTIVATION OF THE POTATO. O 

coveiers of America, or the eariy voyagers to it — it is said 
from Peru. The name in South America was papas. 

It seems that the recommendation of Gerarde was fol- 
lowed, and that the potato was, for a long time, used only 
as a delicacy. It was only cultivated in gardens, and by 
a few persons, for almost a century. The year 1663 is 
mentioned as the date when it began to be more generally 
cultivated. But this was still in gardens. It did not be- 
come an article of field cultiu-e till the early part of the 
eighteenth century, about one century and a quarter before 
this present time. The year 1730 (or as other statements 
give it, 1739) was the date of the first field crop in Scot- 
land, which appears to have preceded the culture at large 
in England. Probably it was not earlier in the American 
Colonies. It is rather a striking instance of the changes 
in the arts and mode of living, from age to age, that 
this plant which, for half a century or more, was only used 
as a delicacy, and was probably regarded as too choice to 
pass the lips of laborers, except those who might have 
raised it, and continued so to be used within two centuries, 
is now raised for the fattening of swine. It is produced 
in such quantities in the west as to be sold for fifteen cents 
the bushel ; and in the eastern States has been marketed 
at twenty-five cents. 

This very hardy plant, native to the lower latitudes of 
the temperate zone, is cultivated with success in Norway, 
in lat. 70 north. 

The modes of cultivation of the potato have been al- 
most as various as the cidtivators ; and indeed the soil 
may be varied somewhat to suit the different varieties. 
Some varieties succeed best on dry, mouldy, rich soil; 
others do well on moist grounds. Mr. Johnson, however 
recommends one soil as best for all kinds. The amount 
of the product, and the quality of the potato depend a ery 



6 HISTORY OF THE USE AND 

much on the character of the soil. Mr. Johnson says, 
" No inhabitant of the garden varies more in quality in 
different gardens than the potato : for a variety will have 
a strong, unpleasant flavor in one soil, that has a sweet, 
agreeable one in another. In a hea\y, wet soil, or a rank, 
black loam, though the crop is often fine and abundant, it 
is scarcely ever palatable. Silicious soils, even approach- 
ing to gravel, though m these last the tubers are usually 
corroded or scabby, are always to be planted in preference 
to the above. A dry, mouldy, fresh and moderately rich 
soil is unquestionably the best for every variety of the 
potato. The black skinned and rough red thrive better 
than any in moist, cold soils." It becomes of course 
important in choosing seed potatoes, to consider the na- 
ture of the soil and climate. In England the modes of 
cultivation have been various: and are known by the 
distinguishing names of dibbling, drilling, furrow-planting, 
holeing-in, trenching-in, and bedding in. The last is used 
in wet soils. In this coimtry the mode of cultivation is 
more uniform. 

A marked difference has been found in the nutritive 
quality or rather nutritive quantity of potatoes, which was 
supposed to be depending on the variety, though it may 
be supposed quite as likely to be derived from the soil. 
Thus from a statement of an analysis made by Mr. George 
Sinclair, an English writer, it appears, as he says, that the 
yam is a very productive variety, attains to a large size, 
but is often hollow, and less nutritive than most others : 
64 drachms afford of nutritive matter 190 grains. The 
ox-noble gave 194 grains to 64 drachms. The purple 
red, to the same quantity, afforded 200 grams: the 
hundred-eye, a very prolific variety, 218 grains : the 
rough-red 250 grains. I know not whether any of these 
varieties have been cultivated in this country. The dif- 



CULTIVATION OF THE POTATO. 



ference is very great, amounting to nearly thirty-two per 
cent ; or 200 bushels of the last would be equivalent in 
nourishment to 264 of the first. 

The Potato has been universally cultivated, both in 
field and garden culture, by the tubers, or the eyes of the 
tuber. This is the only profitable mode of growing them ; 
as, if raised from seed, transplantation is necessary, or 
otherwise, two or three successive crops, before the tuber 
attains a good size. This mode of cultivation being so 
convenient and profitable, has afforded temptation, when a 
good variety was obtained, to continue the cultivation of 
the variety by means of the tuber, too long and pertina- 
ciously, till the decay of old age had manifestly affected 
them. Many varieties obtamed from seed taken from old 
plants would much sooner feel the debility and decay 
of age. Occasionally, Avhen new varieties have been ob- 
tained from seed, those which were not considered to be 
profitable, either for quality or productiveness, were of 
course not continued, but suffered speedily to become ex- 
tinct. On the other hand, those which were considered 
^-aluable it became an object to continue in cultivation, as 
long as possible. Generally when resort has been had to 
seed, it was chosen from those varieties which had long 
been in public favor, and had the highest reputation. 
The degree of excellence is apt to be measured by the 
duration of popular favor ; — and thus the seed has gene- 
rally been selected from the oldest varieties. The culti- 
vator could make no greater mistake than this. The 
seed should be obtained from the most vigorous plants; 
while universally and necessarily those varieties which 
have been in favor twelve or fifteen years have parted 
both with their vigor and their excellent qualities, and 
are entirely misuitable to use for seed. 

It has been a very common practice in this country to 



8 HISTORY OF THE USE AND 

cut the tuber into very small pieces for planting. I can- 
not but attribute the preference for this practice to a want 
of habits of accurate observation, as some of the most 
judicious cultivators, especially Mr. Knight, who to very 
scientific knowledge united very close and accurate ob- 
servation, recommended the planting of the tuber whole: 
and, moreover, for the reason that the young sprout, be- 
fore it has acquired ability to nourish itself by its roots, 
depends for its nourishment on the fecula, or starch, of the 
tuber, which would be supplied more abundantly in the 
whole state, than if divided, and consequently would be 
likely to make more healthy plants. 

The potato in the last century, in England, was visited 
with an epidemic which w^as called by the name of " curl." 
This is mentioned by several different wTiters on vegeta- 
ble physiology and agriculture. "NVhether that was the 
same disease as one of the forms now known among us, 
under the name of rot, it may not be easy to determine. 
In one species of the disease called rot, the edge of the 
leaf becomes curled and black. Fall planting was named 
as a remedy for the curl, but with what success does not 
appear, so far as I am informed. The follo^vuig descrip- 
tion of that disease is found in Mr. Smee's book : 

" Putsche and Vertuch state that the plants which are 
affected by this disease ha^^e an extremely meagre appear- 
ance. The stem is unbranched, brownish green, or mot- 
tled, and here and there sprinkled with rusty spots, which 
penetrate to the pith ; so that it is not white, but rust- 
colored, or sometimes black. The upper surface of the 
leaves is not so smooth as usual, but rough, wrinkled, 
curled or crumpled. The leaves are far more sessile than 
usual, and not of an uniform bro^vnish, or dark green, but 
spotted. The passages for circulation, imbibition, and 
respiration, are none of tliem in a healthy state. The pith 



CULTIVATION OF THE POTATO. » 

is often discolored or dried up, even in the young shoots. 
The starved plant often perishes early in autumn, when 
the tubers should be making their most rapid growth. 
These tubers are scanty and tasteless, juicy and almost un- 
fit for food. Even the color of the outer coat of the tuber 
is changed. The same tuber is in parts brown, in parts 
of a dirty yellow, and sometimes the two tints run into 
each other. Some sorts of potato are more subject to the 
disease than others ; it is more prevalent in fiat countries 
than in more elevated districts." 

" From these descriptions," adds Mr. Smee, " I am much 
disposed to believe that our present gangrene is only an 
exaggerated form of the old curl." He attributes the 
present disease to an insect. 

I have not learned that the cause of the curl was ascer- 
tained, or any remedy found, though a reward was offered 
for the discovery. 

About nine or ten years ago the potatoes began to be 
affected with disease, which appeared in two distinct forms. 
In one of these forms, the appearance is of a black spot 
in the tuber, which is probably a congeries of fungi, or 
small plants of the fungus tribe, not the cause of the 
disease, but collected there as all other plants grow spon- 
taneously on soil suited to their peculiar habit, it being 
the habit of the fungi to draw their aliment from decay- 
ing vegetable matter, not, like plants of a higher order, 
from inorganic matter. The other form of the disease 
makes its appearance on the skin of the tuber, by a cop- 
per colored or ruddy brown spot, and soon after, the fleshy 
part of the tuber becomes soft, something like the rotten- 
ness in an apple, and sjoreads rapidly through the whole 
of the potato. In the mean time the leaf becomes curled 
on the edge, and marked with a dark color. The first 
named form of disease was for a time attributed to insects. 



10 HISTORY OF THE USE AND 

That idea has been found to be eiToneous. The two forms 
of disease arise, as I conceive, from one cause, which was 
mentioned by me many years ago, and Avill be explained 
in these pages, in which I design to show some reasons 
for the opinion. 

Mr. Smee, an English ^\Titer, sj^eaks of two kinds of 
disease, which he calls gangrene, the dry and the moist 
gangrene. These are the same diseases which attack the 
fruit trees, and are usually called canker. The moist 
gangrene is the second species of rot named above. His 
other disease, which he calls dry gangrene, is that condition 
of the potato in which the tuber shrinks internally, and 
leaves a hollow in the centre, sometimes having the form 
nearly of an X. The potato has been frequently marked 
in this way among us, for at least twenty-five or thirty 
years, I think, but certainly for a long niunber of years 
before anything was said about the rot. Considermg this 
as one form of disease then, there appear to be three. I 
refer them all, however, to the same cause. 

Humboldt says the potato is not indigenous in PerUy 
and that it is nowhere to be found wild in the part of the 
Cordilleras situated under the tropics. It has been said 
also that it is not to be fomid in Vii-ginia, or in any part 
of North America ; but in its natuml state is only to be 
found on the western side of South America. The state- 
ment, however, that it is not indigenous to Peru, as well 
as that it is not to be found in North America, appear to 
be erroneous, for Mr. Smee says there is at Chelsea 
Botanical Gardens, in England, a fine plant said to be of 
the wild potato, which he was informed was prociu'ed at 
Santa Fe. There are, however, some two or three places 
thus named, and it is not certain which is mtended. It 
was probably in New Mexico. Santa Fe de Bogota is in 



CULTIVATION OF THE POTATO. 11 

about 4° north ; and the other is in 35° north latitude, 
exactly corresponding to its locality south of the equator. 

M. Poiteau, editor of the Bon Jardiiiier, Paris for 1843, 
says that he formerly received from M. Sabine some tubers 
of the wild potato from Chili, which he supposes the type 
of all the cultivated varieties. The plant is remarkable by 
the very spreaduig roots and by the great number of its 
white flowers; but the tubers, small and brownish, are 
infinitely far from the quality of our good varieties. 

As the question of the locality of this plant is acquir- 
ing interest, I copy from Mr. Smee's work an account of 
it as given therein. It may become necessary to resort to 
the wild stock again to replenish our fields and gardens, 
and in that view it becomes important to ascertam the 
localities, and that our consuls in the vicinity should be 
requested to furnish seed from thence. " Don J. Pavon, 
in a letter to Mr. Lambert, says that solanum tuberosum 
grows Avild in the environs of Lima, and fourteen leagues 
from Lima on the coast ; and I myself have found it in 
the kingdom of Chili ;" and Mr. Lambert adds, " I have 
lately received from M. Pavon very fine wild specimens of 
solanum tuberosum, collected by himself in Peru. In 
Chili, it is generally found in steep rocky places, where it 
could never have been cultivated, and where its introduc- 
tion must have been almost impossible. It is very common 
about Valparaiso, and Cruikshank has noticed it along the 
coast for fifteen leagues, to the northward of that port : 
how much farther it may extend north or south, he knows 
not." 

A further account of some tubers brought from the 
same vicinity is related by Mr. Smee. He says, " Cald- 
cleugh, who had been sometime resident at Rio Janeiro, 
holding the office of Secretaiy to the British Minister, 
brought with him two tubers of the wild potato, which 



12 HISTORY OF THE USE AND 

he sent to the Secretary of the Horticultural Society of 
London, mth the following letter, which is to be found at 
p. 249 in the fifth volume of the Transactions of the 
Society. 

"It is with no small degree of pleasure that I am 
enabled to send you some specimens of the solanum tu- 
berosum, or native wild potato of South America. It is 
foimd growing in considerable quantities in ravuies in the 
immediate neighborhood of Valparaiso, on the western side 
of South America, in latitude 34 J degrees south. The 
leaves and flowers of the plant are similar in every respect 
to those cultivated in England and elsewhere. It begins 
to flower in the month of October, the spring of that cli- 
mate, and is not very prolific. The roots are small and of 
a bitterish taste, some with red, and others with yellowish 
skins. I am mclined to think that this plant grows on a 
large extent of the coast, for in the south of Chili it is 
found, and is called by the natives maglia., but I cannot 
discover that it is employed to any pui-pose. I am indebt- 
ed for these specimens to an ofiicer of His Majesty's ship 
Owen Glendower, who left the country some time after 
me."* 

" The two tubers were exhibited to the Society, and a 
drawing made of them before they were planted, (plate 9, 
fig. 2, Hort. Trans, vol. 5). Had there been a third, I 
should have been tempted to satisfy myself as to the real 
flavor which Mr. Caldcleugh, as well as Molina, describes 
as bitter. They were planted separately, in small pots, 
and speedily vegetated. They grew rapidly, and were sub- 
sequently turned out into a border, at about two feet dis- 
tance from each other, when they became very strong and 
luxuriant. The blossoms at first were but sparingly pro-. 

* The remainder of this statement is apparently from the gardener, though 
it is not so stated by Mr. Smee. 



CULTIVATION OF THE POTATO. 13 

duced, but as the plants were earthed up, they mereased 
ill vigor, and then bore flowers abundantly; but these were 
not succeeded by fruit. A drawing of a branch was made 
by Miss Cotton, which has been engraved (plate xii., Hort. 
Trans, vol. 5). The flower was white, and diflered in no 
respect from those varieties of the common potato which 
have white blossoms. The leaves were compared with 
specimens of several varieties of the cultivated potato, 
which generally were rather more of a rugose and uneven 
surface above, and with the veins stronger and more con- 
spicuous below, but in other respects there was no differ- 
ence between them. The pinnulse which grew on the sides 
of the petiole, between the pinnae of the leaves, were few, 
not near so numerous as in some varieties of the cultivated 
potato ; but in specimens of other varieties that were ex- 
amined, their leaves were destitute of pinnulse, so that the 
existence of these appendages does not appear to be so 
essential a characteristic as has been supposed, and as is 
stated in the supplement to the " Encyclopedia." 

" The plants have been recently taken up, and all doubt 
respecting them is now removed ; they are unquestionably 
the solanum tuberosum. The principal stems, when ex- 
tended, measured more than seven feet in length. The 
produce was most abundant; above six hundred tubers 
were gathered from the two plants. They are of various 
sizes, a few as large, or larger than a pigeon's egg, others 
as small as the original ones, rather angular, but more 
globular than oblong; some are white, others marked 
with blotches of pale red or white. Two of these were 
selected to be drawn, and are represented (plate ix., flg. 3, 
Hort. Trans, vol. 5). The flavor of them when boiled was 
exactly that of a young potato. 

" The compost used in moulding up the plants was very 
much saturated with manure, and to this ckcum stance I 



14 HISTORY OF THE USE AND 

attribute the excessive luxuriance of the growth of the 
stems. Had common garden mould been applied, they 
would not probably have grown so strong ; and I suppose 
that whilst the plants were thus rapidly making stems and 
leaves, the formation of the tubers was delayed, for the 
production of these has been the work of the latter part 
of the season. They cannot be called fully ripe, nor have 
they attained the size Avhich they probably might have 
done, if they had been formed earlier." 

Mr. Smee adds, " I am informed by Mr. Thompson that 
this vrild potato was lost from the Horticidtural Gardens, 
many years ago." 

The foregoing account, presenting the potato in its na- 
tive locality and wild condition, and also an authentic re- 
lation of the process and mode of cultivation, and the 
success of the attempt, by which the change from the wild 
to the cultivated state is so well shown, was considered a 
matter of so much interest to cultivators, as well as to 
naturalists, that it has been inserted here entire. 

From this account of the locality of the potato, it must 
be supposed that a mountain country is most congenial to 
its habit, and that the most suitable climate is to be found 
in lat. 35°. The mountains of Carolina would answer 
these conditions ; and it is indeed probable that here origi- 
nated those specimens which Raleigh first transplanted 
thence to England. ' 

The potato takes a foremost rank among those matters 
fitted for nutriment, both of men and animals; The pro- 
portion of nutriment is very large. Beside its esculent 
use, it is employed in the arts for making starch and 
whiskey. 

The varieties of the potato are veiy numerous. I have 
seen a list of one hundred and sixty kinds now or lately 
cultivated in the gardens of the Horticultural Society, in 



CULTIVATION OF THE POTATO. 15 

England ; which probably does not include all which are 
cultivated m that country. Whether they are as numer- 
ous in France, I do not know. I have seen about twenty 
named of the kinds raised there. In this country they 
are probably as numerous as in England. Mr. Cole, late 
editor of the New England Fanner, raised forty new 
varieties from seed. In Geimany the varieties are but 
few. 

From an account in the Quarterly Journal of Agricul- 
ture, it must be inferred, either that Gerarde's idea of the 
potato being held as a delicacy was not adopted very 
generally, or that the duration of this degree of favor to it 
was short, since that work would have it believed that 
some thii'ty or forty years later there was a strong preju- 
dice against it. The statement there is, that prejudice for 
a long time retarded the general use of the potato. They 
were Ifeft, it is said, in the ground from year to year, a few 
being used in the autumn ; the parent plants being covered 
with litter to save them from the winter's frost.* The 
progress of the cultivation was afterwards greatly retarded 
by the fact that " potatoes are not mentioned in the Bible," 
which was deemed a good reason for rejecting them. Ig- 
norance of the proper mode of cooking them (an evil that 
has not yet been wholly remedied) also retarded their cul- 
ture. ^ A person who had been invited to partake of the 
first mess of potatoes in the county of Forfair, Scotland, 
about 1730, related that the roots had been merely heated, 
and that they adhered to the teeth like glue ; while their 
flavor was far from agreeable. The food was about to be 
Condemned, through the ignorance of the cook, when the 
accidental arrival of a gentleman who had tasted a potato 
in Lancashire, caused the rejected roots to be remanded to 

* This care of the plant does not confirm the statement in regard to preju- 
dice. 



16 PHYSIOLOGY OF VEGETABLES. 

the hot ashes, and they became as dainty as they had been 
before nauseous. It is less than seventy years, by the same 
account, since any particular attention has been paid, in 
France, to the cultivation of the potato.' They were long 
regarded as unwholesome, only fit for cattle, or the most 
wretched of human beings. The mode of cooking pota- 
toes in France now is so diversified, that, it is said, a gen- 
tleman dined a party of friends entirely on them, and 
sumptuously too, they being prepared in thirty-two differ- 
ent modes. 



PHYSIOLOGY OF VEGETABLES. THEIR STRUCTURE AND 

ECONOMY. 

It may aid us somewhat in coming to a correct con- 
clusion on the question of the origin and cause of the 
disease of the Potato, to bear in mind the general structure 
of vegtables and the functions performed by the several 
parts, and the purpose and result of these functions in 
their separate and united action, or what may be termed 
the economy of the plant. 

The plant consists of root, stem, leaves and flowers ; or, 
botanically speaking, of root, herbage, and fructification, 
each of which performs a diff*erent function, carries on its 
own process, and has a different part and office in pro- 
ducing the general result, or in the vegetable economy. 
The several parts seem not to differ so much in structure 
as in function ; all of them being made up of ceUs, tubes, 
and vesicles, and the root, stem, and leaf being each pro- 
vided with a framework of fibre, and each coAered with a 
cuticle or skin. The function of the root is to draw uj) 
moisture from the ground, wliich is, through the medium 
of the trunk, and by some mysterious agency, convexted 



THEIR STRUCTURE AND ECONOMY. 17 

into sap and carried to every portion of the plant ; — is 
further changed by the action of the leaves into a sap 
having different qualities from the ascending sap, and is 
then made to return again through the plant in its 
changed form ; as the blood of man receives a change in 
its passage through the lungs, and is returned through his 
system in the form of arterial blood. This change per- 
formed on the sap by the leaves is so great that in some 
plants in which, later in the season, it becomes highly 
poisonous or narcotic, it is in the spring safe and whole- 
some to be drank. 

The functions of the stem and branches are, to pass 
the ascending and descending sap to all parts of the plant. 
It is not easy in all cases to distinguish what is root and 
what is stem in a plant. Some parts are commonly 
regarded as roots which are in feet stems. The position 
only of being above or below the ground does not deter- 
mine the question. The stem sometimes grows beneath 
the gromid. The root has a downward tendency, and ab- 
sorbing, sponge-like pores, by which the aliment is taken 
up for the plant. The stem commonly has leaf-buds. 

The leaves perform the functions of respiration and 
perspiration ; and the effect produced upon the sap by 
these two actions is, as above stated, to work a change in 
it, by which, in some plants the quality of the sap is 
materially altered. They are supposed also to perform 
the digestion of the plant, assimilating the ahment mto 
the peculiar secretions ; as well as absorption. 

The internal organization, or anatomy of plants consists 
in a series of tubes, cells and vesicles regularly arranged, 
and through which that action is carried on which con- 
stitutes the vitality of the plant, or vegetable life. 

The seeds of pla,nts have four parts, each of wliich is 
easily discernible in the pea or bean. Fu'st, the point, 



18 PHYSIOLOGY OF VEGETABLES. 

by which it is attached to the receptacle, or in the pea 
or bean to the pod, in the corn, to the ear. This is 
termed hilum or scar. Second, the thin hnsk or skin, 
which, when the seed is ripe, seems to be a part altogether 
useless, forms an envelope or bag very necessary to contain 
it in its earlier state, when it is a mere juice, or as it is 
caUed by the farmer, in the milk. Third, the cotyledon 
which is the main fleshy part of the seed, constituting 
its principal bulk, most frequently divided into two 
portions by a seam, as in the bean, which easily opens. 
Fourth, and the part which is all important in producing 
a new plant is the corcule, the most essential part in the 
germination of the plant, consisting of radicle, which 
descends and forms the root, and plume, which ascends 
and forms the stem. It lays near the scar or hilum, 
and when the bean swells and opens is distinctly seen 
in the shape of a fleshy filament which is the sprout 
or shooting of the new plant. The essential element in 
the constitution of the seed, which appears to be necessary 
to its fructification and the reproduction of new life by 
development of the embryo, is starch, w^hich, by the ap- 
plication of due heat and moisture, effects the germinating 
process, in which the starch is converted into sugar. 

The bark or outer covering of plants consists of an 
outer coat, called epidermis or cuticle, of a cellular integu- 
ment, and of an inner coat or liber. The cellular integu- 
ment of the bark, by extension forms the leaf, "with a 
covering, on both sides, of the expanded cuticle. The cel- 
lular tissue in fact not only is extended mto the leaf, but 
pervades the whole body of the plant, through the inner 
bark and the heart of the wood, and the pith. The wood, 
or heart, of a plant is formed by a number of layers, con- 
centrically arranged, each years growth constituting one 
layer, with a cellular membrane intervening each, through 



THEIR STRUCTURE AND ECONOMY. 19 

whicli the juices of the plant are circulated. The pith is 
in the centre of the stem, constituting usually, in herba- 
ceous plants, a large part of the stem in bulk. In such 
plants it usually contains a large share of the juices. It 
sometimes forms an article of food, as the pith of a species 
of palm, called the sago palm, and also of a wax palm of 
South America. It is probable also that the pith of the 
sugar cane and of Indian corn might be very palatable 
and nutritious food. Between the bark and the proper 
wood is a layer of sap or alburnum, in perennial plants, 
which, however, is subsequently converted mto proper 
wood. 

Throughout these several parts of the plant, are dis- 
seminated the vascular and cellular openings or tubes 
which serve to convey the air, juices and alimentary mat- 
ter from one part to another. These consist of the medul- 
lary appendices, ]3roceeding from the pith and crossing the 
grains or layers of the trunk or stem, in a radiate direc- 
tion, known by workmen as the silver grain, aii' vessels, 
called trachese, sap-vessels, and vessels which secrete the 
proper juices of the plant. 

The roots absorb water, and substances contained in the 
water in solution, which is immediately converted into 
sap, and, m that form, passed upward to the branches, 
leaves and other parts. In the passage through the leaves 
it undergoes another change, which has been likened to 
the change which takes place in the blood of man, from 
venous to arterial, in passing through the lungs. Other 
vessels are appointed to carry on the proper secretions 
of the plant by which are produced tannin, fixed and 
volatile oils, turpentine, giun, rosin, starch, wax, tallow, 
camphor, sugar, opium, various coloring matters, and acids. 

The buds are the embryo branches, which from time to 
time continue to be developed while the life of the plant 



20 PHYSIOLOGY OF VEGETABLES. 

remains — constantly changing the form, and multiplying 
the limbs as well as enlarging the extension of the plant. 
In this, vegetable life differs from most of the animal 
world. Though in some of the lower orders of animals, 
as in the frog, something analogous exists, the animal not 
being evolved from the embryo in its perfect shape, but 
having new limbs developed after it has been in life some 
days. But with few exceptions the perfect animal is at 
once evolved from the embryo. It is different in the 
vegetable creation. The plant is contmually putting forth 
buds, which if suffered to remain and vegetate on the 
parent stock, become new branches only, of the parent ; 
but if removed from the stem and placed in the earth, in 
a condition for their growth become developed into a fidl 
and perfect plant, instead of a branch of the parent. In 
this case, however, it is merely the extension or multipli- 
cation of the form of the life already in being, and not a 
new life — not a new individual. 

The principal matters absorbed by the roots of all plants 
are water and carbonic acid. These are essential to their 
growth. In the act of respiration they throw out oxygen, 
which is a principal constituent of both of those sub- 
stances. And the consequence of setting free the oxygen 
of the water and carbonic acid is the production of gum, 
starch and sugar. Starch, which is very abundant in the 
potato and the cereal grains, is converted into sugar by 
the process of germination, as may be perceived by the 
sweet taste of malted barley. 

The reproductive power of plants is in the seed only. 
It is only by the development of the embryo contained in 
the seed that a new life can be produced. This embryo 
of life is not fvdly developed at once, but continues 
gradually to be developed in the production of new parts, 
as above mentioned by means of the buds, which from 



THEIR STRUCTURE AND ECONOMY. 



21 



time to time put forth. Eacli of these buds, however, 
though it may produce new forms of vegetation, and 
propagate new plants, yet does not reproduce or gen- 
erate new life; but it is merely an extension of the 
life generated from the single embryo of the seed. This is 
generally well understood by cultivators. Having thought 
proper however to state the principle here, and it being 
the basis on which my ideas of the disease rest, a few ex- 
tracts are adduced from some of the writers on the subject 
whose opinions are universally acknowledged, in confirm- 
ation of it. The following is from Dr. James E. Smith, 
one of the most scientific writers on Physiological Botany. 
" By buds, as we well know, plants are propagated, and 
in that sense each bud ts a separate being, or a young 
plant in itself; hut such propagation is only the extension 
of an individual, and not a reproduction of the species, 
as by seed. Accordingly all plants increased by buds, 
cuttings, layers or roots, retain precisely the peculiar 
qualities of the individual to which they owe their origin. 
If those qualities differ from what are common to the spe- 
cies, sufficiently to constitute what is called a variety, that 
variety is perpetuated through all the progeny thus ob- 
tained. This fact is exemplified in a thousand instances, 
none more notorious than the different kinds of apples, 
all which are varieties of the common crab, Pyrus malus ; 
and I cannot but assent to Mr. Knight's opinion, that 
each individual thus propagated has only a determinate ex- 
istence, in some cases longer, in others shorter ; from 

WHICH CAUSE MANY VALUABLE VARIETIES OF APPLES AND 
PEARS, KNOWN IN FORMER TIMES, ARE NOW WORN OUT, 
AND OTHERS ARE DWINDLING AWAY BEFORE OUR EYES. 

* * Gardeners know how many of the most hardy 
perennial herbs requu'e to be frequently renewed from 



22 PHYSIOLOGY OF VEGETABLES. 

seed, to exist in full vigor ; and though others appear, to 
our confined experience, unlimited in that respect, we 
have many reasons to believe they are not so. Propaga- 
tion by seeds, is therefore the only true reproduction of 
plants, by which each species remains distinct, and all 
variations are eifaced ; for though new varieties may arise 
among a great number of seedling plants, it does not 
appear that such varieties owe their peculiarities to any 
that may have existed in the parent plants. [Smith's 
Phys. and Sys. Botany, pp. 121, 122.] 

Again this author says, [Chap. 19,] "Having examined 
the general structure and external form of plants, we now 
come to more important and even essential, though more 
transitory organs — the flower and fruit, or parts of fructi- 
fication. By these each species is perpetually renewed 
without limits, so far at least as the observation of man- 
kind has reached ; while, as we have already mentioned, 
all other modes of propagation are hut the extension of an 
individual, and sooner or later terminate in its 

TOTAL EXTINCTION. [lb. p. 194.] 

Mr. Raspail says, " The substitution of a bud for the 
seed as the germ of a plant, is rather a transplantation 
than a reproduction. It is only a continuance of the 
same individual plant." [Raspail, p. 194, 196.] 

Dr. Darwin, in his work entitled Phytologia, or the 
Philosophy of Agriculture, calls this propagation by buds, 
" lateral production," and " paternal offspring." Some of 
his own ideas upon buds and their faculty of propagation 
are very curious and instructive, while some are conjec- 
tural and imaginative. He had studied the whole physi- 
ology of the vegetable world, with a zeal and intense ardor, 
and especially what relates to the function of reproduction 
and propagation. He says, in Sec. 7, 1, 3, p. 95, "An- 
other curious occurrence in this lateral production of 



THEIR STRUCTURE AND ECONOMY. 23 

vegetables by their buds has been lately published by Mr. 
Knight in the Ph. Trans, for the year 1795, who observes 
that those apple trees which have been continually propa- 
gated for above a century by ingrafting, are now become 
so diseased by canker or otherwise, that though the fruit 
continues of the same flavor, the trees are not worth pro- 
pagating ; as these grafts, though transplanted into other 
trees, he esteems to be still a7i eloiigation of the original 
tree, and must feel the effect of age, like the tree they were 
taken from. If this idea should prove true, on further 
examination, there is reason to suspect the same may occur 
in the too long propagation of plants from bulbs and 
wires, as potatoes and strawberries, which may have occa- 
sioned the curled tops of potatoes, and the black blight in 
the flowers of the hautbois strawberry, which some have 
ascribed to its only bearing male flowers; the cure of 
which must arise from our applymg to other varieties more 
lately derived from a seminal offspring. 

It is true that Dr. Darwin does not agree to the view 
therein suggested by Mr. Knight. He thinks the disease 
or degeneracy of plants raised from buds is not to be 
ascribed to the age of the original seedling stock, but to 
hereditary diseases derived from that stock, or some of the 
intervening line, which in the seminal progeny would be 
counteracted by mtermixture. This might undoubtedly 
sometimes be the case. Though as a scientific question, 
there is some difference in the two theories, yet in agricul- 
tural practice, and as a question of cultivation, it becomes 
a difference almost without a distinction, and not import- 
ant enough to be mentioned ; the source of disease in each 
case being paternal, and requiring the same remedy. 



24 NATURAL HISTORY 

NATURAL HISTORY OF THE POTATO. 

The potato is a plant of the class pentaiidria, order 
monogynia, and included by Linnaeus in the natural order 
luridse, and by Jussieu in that of solanese. The genus, 
solanum, comprises a large number of species. Botanists 
have mentioned about an hundred. Some of these, beside 
the potato, are among the most valuable esculents. Of 
these are the solanum lycopersicum, familiarly known to 
us as the tomato, a corruption of the Spanish name esto- 
matos ; and the solanum melongena, or egg plant, a favorite 
vegetable in the States farther South, The potato plant 
has its botanical name from the edible tuber, solanum tu- 
berosum. The common name potato seems to be a cor- 
ruption of the name by which the sweet potato was known 
at the time the other was first seen by the English, which 
was batatas. The name of our potato was opanawk in 
Virginia, and in South America papas. 

Others of this genus are acrid, noxious and poisonous. 
It comprehends a great number of species called night- 
shade, among them solanum dulcamara, woody nightshade, 
or bitter-sweet, and solanum nigrum, common nightshade. 
To the order solanete, belong also nicotiana, tobacco ; da- 
tura, thorn apple; digitalis, foxglove; hyosciamus, henbane; 
atropa, deadly nightshade. 

In some species of the genus solanum, the flowers are 
very handsome, and the fruit ornamental. The corolla is 
generally blue, purple, white or yellow. The fruit yellow 
or red. The herbage is foetid and narcotic. Flowers 
without scent. Fruit often nauseous, and not eatable with- 
out dressing. The solanum lycopersicum is, however, as 
is well known, highly palatable and delicious as taken 
from the vine. Several species of the solanum are culti- 
vated. Beside the potato, tomato, and egg plant, the 



OF THE POTATO. 



25 



Ethiopian nightshade; the woody nightshade, or bitter 
sweet ; the mullein-leaved nightshade ; the shrubby ; the 
oak-leaved ; the dug-fruited ; the Indian ; Carolina ; black- 
spined; Palestine. 

The potato is an annual plant. Though originally 
found in but few places, it has become naturalized 
throughout this continent and Europe, and its habitation 
now extends from the equator to 70 degrees north. It 
was found native in Peru and Virginia. In its native 
state the tuber is quite small, being about the size of a 
nutmeg ; and it has been brought to its present increased • 
size by cidtivation. 

The varieties that have been produced by cultivation 
are almost endless. The principal varieties, hoAvever, are 
considered but two, the white and the red ; the others are 
rei^arded as subvarieties. 

The potato has sometimes been described as a tuberous 
rooted plant. This is, however, inaccurate. The tuber 
has not the structure and cannot perform the function of 
a root. The office of the root is to draw up aliment in 
the shape of water and earthy matters, to be conveyed to 
all parts of the plant, for its nourishment, and to this end 
it is fiuiiished with pores, by which the absorption is 
eifected. This is not the office of the tuber, and its struc- 
ture is not adapted to this end. On the other hand the 
matter of the tuber is well elaborated in the economy of 
the plant before it is deposited, and its 0"\vn nourishment 
is apparently the chief end and object of that economy. 
Not performing the function of a root, it is not then accu- 
rate to describe it as a root. 

It is well known that the tuber of the potato plant 
consists in great part of starch. It is also known that the 
same ingredient enters largely into the process of fructifi- 
cation in all plants, and that there is a deposit of this 
3 



26 NATURAL HISTORY 

matter made in the receptacle or other part of the flower 
at the period of the formation of the fruit, to assist in the 
office of forming and bringing it to perfection. Now it 
would seem to be the case that the proper roots of the 
potato di-aw from the earth much more of the elements of 
this substance than can be used in the process of fructifi- 
cation ; and the surplus is continued in the circulation of 
the plant, and returned with the returning juices, and at 
the bottom of the stem is concentrated and developed in 
the tuber, which makes the most important and valuable 
part of the plant. The proper root has performed its ap- 
propriate function of dramng up the necessary nourish- 
ment of the plant before the tuber has begun to form. 
The true root is composed of the small filaments which 
are connected with the stem ; and the potato is, in fact, a 
fibrous-rooted plant, having roots similar to the grasses. 
The tubers are not attached to the roots, but to runners 
proceeding from the base of the stem, which are wholly 
distinct from the fibres which perform the function of 
roots. 

The tuber is now generally considered as a part of the 
stem, an under ground stem, or root stalk. In proof that 
it is such, are mentioned the buds or eyes, which are simi- 
lar to those on the stems and branches of plants, and of 
which it is said roots are deficient, and that these eyes or 
buds of the tuber, like the buds on the twigs of trees, are 
capable of propagating the plant. There seem to be agaui 
some reasons against regarding the tuber as a part of the 
stem. It differs in structure, elements and properties from 
the aerial stem, being more pulpy and juicy, containing 
more starch, and less fibre, and having more nutritive pro- 
perties. This difference is supposed to be sufficiently ex- 
plained by its imderground growth. This condition woidd, 
no doubt, be the cause of some differences, but whether to 



OF THE POTATO. 27 

such an extent does not seem certain. Starch, the prin- 
cipal constituent of the tuber, as has been mentioned, is 
an essential element in the fructification of the plant. 
There being more of this substance, however, elaborated 
in the economy of the vegetable than is required in sup- 
plying the seeds, it may be supposed to be returned 
through the tissues of the plant, and deposited at the base 
of the stem. The tuber, then, might rather be regarded 
as a peculiar secretion of the plant, anomalous in its na- 
ture, than as a portion of the stem. And the period of 
its formation would also favor this idea. On the other 
hand the buds endowed with the faculty of propagation 
present an objection to this supposition, and favor that 
which considers it as a part of the stem. 

In this light it is regarded by the author of an excellent 
volume entitled, "A Popular Treatise on Vegetable Phy- 
siology," pubHshed a few years since in Philadelphia. 
That writer says, " one of the most distorted forms of the 
stem is that which presents itself in the potato. This 
plant grows with an underground stem, sending up its 
flowering bmnches into the air, and sending its roots 
downwards into the earth ; but on this stem it forms, at 
intervals, the tubers or knobs, which constitute such an 
important article of food to man. That these tubers are 
still parts of the stem, is shewn by their power of origi- 
natmg buds, from the pomts commonly known as the eyes 
of the potato. When, therefore, we divide the tuber into 
pieces, keeping an eye in each, from every one of which 
we expect a young plant to spring, we follow, in fact, the 
same plan as that adopted in planting sugar-canes, which 
are not propagated from seed, but by dividing the stem 
into its internodes, and laying each of these separately in 
the ground. The quantity of fleshy matter deposited in 
the potato serves for the nouiishment of the growing buds 



28 NATURAL HISTORY 

before theii' roots are formed ; and thus it is that, if ex- 
posed to a warm and moist atmosphere, they are liable to 
sprout, without the. contact of earth. It is remarkable 
that in their native climate, (the tropical part of South 
America,) the tubers of the potato are extremely small^ 
and that they become so when plants are raised from 
British stocks in any countries equally hot." 

This liability to sprout, however, when exposed to 
warmth and moisture, does not depend on the fact that 
the fleshy matter of the tuber serves for the noimshment 
of the plant, nor is peculiar to that plant. It is the case 
with other plants that the starch of the seed furnishes 
nutriment to the young shoot, and also, if exposed to the 
conditions of warmth and moisture they will sprout, though 
not in contact with earth. It is in the same way that bar- 
ley is malted, and that seeds are rendered unproductive by 
too long keeping. 

On the other hand, the tuber is considered by Dr. Smithy 
a most excellent authority on all matters of vegetable phy- 
siology, as a root, and the potato is mentioned by him 
(page 98) as an example of a tuberous rooted plant. The 
reasons already mentioned must be considered, however, 
sufficient to confute this idea, though countenanced by so 
distinguished a physiologist. 

But whatever may be the relation of the tuber to the 
vegetable being, whether it be part of stem or root, or 
whether it be neither, it is sufficient for the present pur- 
pose to know that it is not the seed of the plant. It does 
not bear any analogy to the fruit, is not the pericarp, does 
not contain the seed ; and whether it be a part of the root 
or an underground stem, by propagation by it of new 
plants, the j)roduction of a vuie is not a reproduction of 
new life, but merely the production of a new form by ex- 
tension of the old life, analogous to the production of new 



OF THE POTATO. 



29 



Starch. 


Fibre. 


Water. 


548 


477 


5000 


667 


616 


4737 


695 


622 


4713 



forms by layering or grafting, by which a bud, instead of 
being the germ and sprout of a new branch, is made to 
take the form of a new, perfect plant, aU parts, both root 
and stem proceeding from it. It is an extension of the 
same life, not a production of a new one. 

Some varieties of the potato were found, on analysis, 
to contain as follows in 7000 grains or one pound 

Soluble 
matter. 

variety called the bread-fruit, 975 
" Barbadoes, 980 

" " black-kidney, 970 

the soluble matters consisted of gum or mucilage, extrac- 
tive, and saline matters. Other experiments show a large 
quantity of potash in the potato, which in this result may 
have been partly contained in the saline matters, and 
partly in the fibre. 

The locality of the potato does not seem to be tropical, 
as stated by the author quoted on the preceding page. 
Humboldt expressly asserts that it is not to be found there. 
By the account given in the historical part of these pages, 
its habitation seems to be about lat. 35°. That is the 
latitude of Valparaiso, and also of Santa Fe (New Mex- 
ico) ; and the tract of country called Virginia, at the time 
of Raleigh's visit, or rather so named by him, covered the 
same latitude. It is probable that the plant may be found 
at this time wild in the mountains of North Carolina. 

The alimentary and nutritive properties of the potato 
are very great. Few plants contain a larger proportion. 
They are said to furnish all the elements necessary to the 
support of man, and they have sometimes constituted his 
sole food. 



30 DISEASES OF PLANTS. 



DISEASES OP PLANTS. THE POTATO DISEASE. 

The vegetable world is subject to a variety of diseases,- 
That which has life must experience decay and death. 
Unless endowed with immortality, there must be a disso- 
lution of the physical organism ; and of course there must 
be disease. Vegetable life, as well as animal, is subject to 
these conditions. The nopal, or Indian fig, cactus cocci- 
nellifer, a tree of South America, is very subject to gan- 
grene, which disorder shows itself by a black spot in the 
leaf, and spreads till the leaf or branch drops off, or till 
the plant dies. The same plant is also subject to a sudden 
decay of the vital principle. It changes in an hour from 
a shming green to a dead yellow color, and becomes quite 
rotten. The honey-dew is a disease to which the hop and 
other plants are subject. The blight, mildew, mould, 
smut, ergot, &c., are, some of them, produced by fungi, 
which vegetating in the grain cause a drying of the sap, 
and a destruction even of the organic structui-e of the 
gram. This is the case with smut, as it is usually caUed 
mth us ; sometimes called blight, dust-bran, bui-ntcorn, in 
England, and known by a variety of names. The disease 
attacks the gluten especially, and also prevents the forma- 
tion of the starch. It is chiefly confined to the cereal 
plants. The disease is communicable from the parent 
seed, though the diseased seed, if well rubbed between the 
hands and washed clean, will produce healthy grain. 

The mildew, commonly called rust by our farmers, a 
disease very different in its appearance from the smut, is 
yet caused in the same way, by a fungus, and one very 
nearly allied to the smut. It becomes attached to the 
stem, instead of the grain, and its roots penetrating into 
the plant, are nourished by the sap which should go to 



THE POTATO DISEASE. 31 

the development of the grain. In consequence, the grain 
becomes shrivelled. This disease is mentioned in Deuter- 
onomy, and by some of the prophets, and was known also 
to the Greeks and Romans, says Mr. Johnson, author of 
the Farmers' Encyclopedia, yet no cui'e has to this day 
been found for it ; and though Theophrastus wrote upon 
it m his history of plants three centuries before Christ, 
the cause of it was not suspected till within a century of 
the present time. It was first mentioned by F. Fontana, 
an Italian, m 1767. All soils, all varieties of grain, and 
all situations are liable to this epidemic, though it has 
been said that high situations are not affected to the ex- 
tent which grain in the low valleys suffer. The form of 
blight known as red-rust, and another called red-gum, are 
both caused by fungi, the first of which attacks the stem, 
like the rust or mildew, the other attacks the grain itself. 
The ergot commonly attacks rye, and other gramineous 
plants. The grain or berry becomes of a dark color, and 
elongated like a horn. This is also a parasitic fungus, like 
those above named.* 

The canker, sometimes caUed dry gangrene, which at- 
tacks apple trees, is well known to most farmers. That 
disease is said on very good authority to attack generally 
two classes of subjects ; the aged and those Avhich have 
had an extraordinarily vigorous growth — wliich conditions 
would show the same cause of disease in both, that is, a 
waste of life, or dimunition of the vital principle. 

The fungi, some of which to the common eye, have the 
appearance of mere earthy excrescenses or atmospheric 
concretions, are in reality endowed with vegetable life. 
Not only the mushrooms, but puff-balls, and some kinds 

* The fungi are spoken of here as causing the disease. The peculiar ap- 
pearance in these cases is from the presence of fungi ; but from their habit it 
must be supposed that disease existed previous to their attack. 



32 DISEASES OF PLANTS. 

of moiild, mildew, and blight are organized matter capable 
of reproduction and vegetation. Such are the ergot of some 
plants, and the smut of wheat. These differ from the 
vegetable orders next above them in the scale, prmcipally 
in the aliment required for their support, and the condi- 
tions necessary to their existence. The others drawing 
their subsistence from water, or from the atmosphere, while 
the fungi are nourished by organized matter, animal or 
vegetable, in a state of decay, or in which decomposition 
or some change from a perfectly sound and healthy condi- 
tion has taken place. The fine dust which issues from the 
puff-balls consists of the germs of new plants, which when 
borne through the air by the wind, and finding some sub- 
stances suited to theu' subsistence, are thereto attached, 
and become developed in the ordinary course and manner 
of vegetation. The body of the silk-worm, when about to 
undergo its change to the chrysalis state, presents a condi- 
tion favorable to the growth of these germs, and they fre- 
quently become attached to it, and the vegetation of the 
germ constitutes the disease kno"wn among the silk grow- 
ers by the name of muscardine. And it is probable that 
the selection which is made by epidemic diseases among 
mankind may be owing to this cause ; the miasma which 
is supposed to produce the disease, finding the requisite 
conditions for its growth only in subjects who are in some- 
what impaired health or ^dgor. And this it is, probably, 
Avhicli gives rise to the disputes about the contagious na- 
ture of such epidemics ; some persons living untouched in 
the midst of the disease, while others apparently receive it 
from the infected atmosphere, or contact with others. 

The peculiar condition of timber called dry rot, is also 
occasioned by the growth of these fungi. The fungi may 
cause decay in vegetable bodies which had not pre^dously 
exhibited any signs of disease or weakness ; but they more 



THE POTATO DISEASE. 



33 



commonly only serve to hasten it where previous disease 
had existed, which is usually the condition of plants 
to which they become attached. These very minute vege- 
table bodies, like the smaller insects which are among the 
lowest m the scale of animal life, are extremely prolific. 
They are produced in such profusion that, borne upon the 
wind, they are ever ready to fix Avherever the conditions 
are suitable to their nourishment. 

It is very probable that the presence of some fungi of 
this sort in the potato may give rise to some of the dis- 
tinctive characteristics appearing in the potato disease, 
called the rot. The writer does not profess certainty on 
this point. He has not made any examinations to deter- 
mine if it may be so, or not. It has been stated on suffi- 
ciently good authority to be so. In his view it is not 
essential ; for the theory which he intends to establish is, 
that if fungi are present in the diseased potato, they are 
there because the tubers are previously in a condition 
suited to afibrd them aliment — that is, they are already 
m an unhealthy, enfeebled condition. That condition is 
old age. All vegetable, as well as all animal life, has a 
limit to its existence. A'S^iatever has life is subject to 
death, decay and disease. The potato has been propagated 
for the most part from sets or buds, for a long course of 
years. Occasionally a new variety is raised from the seed, 
but most of those at present in cultivation and use have 
been raised for many successive years from the buds or 
eyes of the tuber, which is only an extension of the same 
indi\idual life, and not a production of new life. In 
addition to this, it is subject to a forced cidtivation, in a 
climate to which it is not indigenous. These conditions 
would be likely to have much efiect in shortening life. 
Though therefore the immediate disease may be either in 
part, or in whole the existence of fungi within, yet there 
is an idtimate cause to which the presence of these fungi 



34 



DISEASES OF PLANTS. 



is owing, and that is the condition of old age. That is 
the disorder which is to be remedied. 

The writer ventured to suggest this opinion in a para- 
graph of an agricultural paper in the winter of 1845 — 6. 
Since that time statements have been made in some of the 
papers going to show that some kinds of potatoes recently 
from seedlings had partaken of the disease. The fact is 
also stated by Mr. Smee. This at first sight might seem' 
to invalidate the theory here advanced. But on the sup- 
position that fungi are partly concerned in it, there are 
two considerations, which, if "due weight is allowed to 
them, must exclude such a conclusion. The first of these 
considerations is, that though old age is peculiarly subject 
to the disease, nevertheless it may sometimes attack the 
young. The supposition that old age, in man, makes him 
peculiarly liable to disease and death, and to general de- 
bility, is not repelled by the occurrence of death or sick- 
ness in the case of a child. Old age must necessarily be 
subject to them. They may sometimes occur in child- 
hood. The second consideration will be at once perceived 
to have force when the nature of the fungus is con- 
sidered. For, supposing the presence of this plant ; 
which having life is capable of reproduction, and that 
the reproduction is by immense numbers at a time: 
now in proportion to the proper subjects of the disease 
on which the fungi would naturally fix and find aliment, 
would they be increased, each new subject being a nursery 
for innumerable individuals constantly reproduced from 
their parent fungus. Each new reproduction constitutes 
a new stock of disease which when produced seeks a new 
subject on which to fix, and, wafted by the wind, finds for 
the most part a place of deposit in a diseased plant, or one 
in decomposition, particularly suited to it, hut sometimes 
fixes on healthy plants, which become diseased by its jjre- 
sence. Thus the fungi nurtured in those potatoes which 



THE POTATO DISEASE. 35 

were suitable to it, those debilitated by old age, have be- 
come indefinitely multiplied, and so numerous that, in some 
cases, they may fix and feed on healthy plants, as well as 
on the sickly. In this way the epidemic becomes gen- 
erally prevalent. 

Again if a plant is rais/sd from a seed which was pro- 
duced by a diseased or very aged parent, it would be 
liable to disease almost as much as a bud taken from the 
old stock. From these considerations it is evident that 
the circumstance of seedling or new plants being attacked 
by the disease, does not in any degree invalidate the 
theorem here asserted, which is founded in an immutable 
law of nature, attached to all forms of life, and to all or- 
ganized matter ; and that law is dissolution. 

In the Farmer's Encyclopedia, by C. W. Johnson, Em- 
erson's Phil. Ed., 1844, art. Canker, it is said, "although 
young trees are liable to this disease, yet their old age is 
the period of existence most obnoxious to its attacks. It 
must be remembered that that is not a young tree which 
is lately grafted. If the tree from which the scion was 
taken is an old variety, it is only a midtiplication of an 
aged individual. The scion may, for a few years, exliibit 
signs of mcreased vigor, owing to the extra stimulus of 
the more abundant supply of healthy sap supplied by the 
stock, but the vessels of the scion will, after the lapse of 
that period, gradually become as decrepid as the parent 
tree. The unanimous experience of naturalists agree in 
testifpng that every organized creature has its limit of ex- 
istence. In plants it varies from the scanty period of a 
few months, to the long expanse of as many centuries ; 
but, of all, the days are numbered; and though the gar- 
dener's, like the physician's skill, may retard the onward 
pace of death, he will not be permanently delayed. In 
the last period of life they show every symptom that ac- 



36 DISEASES OF PLANTS. 

• 

companies organization in its old age, not only a cessation 
of growth, but a decay of former developments, a languid 
cii'culation and diseased organs." 

" The canker, as already observed, attends especially the 
old age of some fruit trees, and of these the apple is, most 
remarkably, a sufferer. ' I don't mean,' says Mr. Knight, 
' to assert that there ever was a time when an apple tree 
did not canker in unfavorable soils, or that highly culti- 
vated varieties w^ere not more generally subject to the dis- 
ease than others, where the soil did not suit them ; but I 
assert, from my own experience and observation witliin 
the last twenty years, that this disease becomes progres- 
sively more fatal to each variety, as the age of that variety, 
beyond a certain period, increases ; that all the varieties of 
the apple which I have found in the catalogues of the 
middle of the seventeenth century, are unproductive of 
fruit, and in a state of debility and decay.' 

"Among the individuals particularly liable to be in- 
fected, are those which have been marked by an excessively 
vigorous growth in their early years." [Art. Canker.] 

The disease now prevalent in the potato, as was briefly 
stated in the first chapter of this tract, appears in three 
forms. The first a shrinking internally, leaving a hollow 
in the centre. The walls of this cavity are usually of a 
darker hue than the body of the tuber, sometimes havmg 
a resemblance to the rust of iron. The adjacent part of 
the tuber is frequently hard, so that when the potato is 
fully cooked by boiling, and become soft and mealy, this 
part remains hard, approaching in this respect to the hard- 
ness of callous flesh, or horn. This is considered by Mr. 
Smee one form of gangrene, and of course, being unat- 
tended with moisture, the dry gangrene. Another form, 
which he also calls gangrene is that where the tuber be- 
comes soft, pulpy and moist, something similar to the rot- 



THE POTATO DISEASE. 37 

tenness in apples. This is the moist gangrene. This is 
the disease which has particularly caused so much loss to 
farmers, so much consternation to those who delight espe- 
cially in ministering to their appetites, and in providing 
pleasant and nourishing food for the earthy and physical 
nature ; and so serious a detriment to the state, in the 
damage to a staple which is food for both man and beast, 
and a source of much wealth. 

There is still a thkd form of disease, which is distin- 
guished by a collection of black, dry matter, in the body 
of the tuber, and which, by whatever name called, was 
pretty extensive in the potato in this country within a few 
years, and is referred to by many persons, who communi- 
cated their observations in relation to it to the public, 
through the agricultural journals. Whether this might 
be a distinct disease, and independent of the cause which 
is here assigned for the other forms of disease may be 
questioned. I refer all, however, as before said, to one 
cause. 

The gangrene may commence, says Mr. Smee, in various 
parts of the plant. It may attack a part of a single leaflet, 
which may die, or any part of the stalk, causing the death 
of the part above. Frequently it is first found in the un- 
derground stem. The tubers themselves finally become 
diseased. When the tuber is affected, parts, here and 
there, become soft, discolored and rotten. Under certain 
circumstances this diseased matter becomes dry, passing 
into dry gangrene ; in others, it remains soft, in the state 
of moist gangrene. Sometimes it commences internally, 
before it appears on the skin. The disease, says the above 
very close and scientific observer, who has made a business 
to watch and study the malady, cannot be said to reside in 
the blotch in the leaf, the dead part of the stem, or the 
rotten tuber. It is a far more hidden affair, having its 



38 DISEASES OF PLANTS. 

residence in the vital elements of the plant ; and therefore 
we may infer that it is a disease connected with the sap 
and cellular tissue, and thereby influencing the vital ac- 
tions which occur between these necessary constituents of 
the organic body. 

The decay and infirmity of old age cannot always be 
exactly measured by a numerical standard. Some men 
have as much decrepitude at sixty as others at ninety. So 
it is iQidoubtedly in vegetable life. Old age may be ac- 
celerated by other causes than time. Temperature or 
moisture, too great heat from the fertilizers used, too much 
stimulus, surfeiting with too great a supply of aliment, too 
much watering, storing in moist cellars, and the Hke causes 
may operate so unfavorably on the potato as to shorten 
the term of existence, without any specific disease, and by 
mere decay of its substance. 

Mr. Berkely considers fungi to be the cause of the dis- 
ease. Mr. Smee combats this theory, and while he admits the 
presence of the fungi, yet justly says that they do not pro- 
duce it, and his observation has shown him that they are 
not present till after the disease has taken place. As his 
remarks on this head are very interesting and the residt of 
close observation, assisted by much science, I transfer them 
to these pages. He says : 

" Doubtless the fungi exercise an important influence 
upon the progress of the disease, although they, most as- 
sm-edly, have not the power of producing it. In fact they 
never make their appearance until the potato plant has 
been previously damaged, and until some portion of it is 
already dead. I have tried several experiments on the m- 
oculation of sound potatoes with fungi, but the result has 
been a comparative failure ; and sound potatoes would re- 
main amongst others abounding in numerous fungi with- 
out being injured." 



THE POTATO DISEASE. 39 

"When the plant is damaged, then these vegetable 
parasites appear, and the function which they are destined 
to perform is highly interesting, and, in fact, a wonderful 
example of natural economy ; for whilst man is careless, 
and allows decomposing bodies to send forth thek putrid 
exhalations, and even buries the dead in the midst of the 
houses of the living, and allows the existence of open 
di'ains, and untrapped sewers, nature, when not interfered 
with, amply provides against the occurrence of such un- 
healthy and offensive conditions by taking effective means 
to remove the dead material." 

" The carrion crow, the vidture, and the jackall, may do 
much; — the maggot, the beetle, and the wasp may do 
much, — towards the removal of dead animal matter ; yet 
to the vegetable parasite is left the duty of annihilating 
the exhalations of putrifying vegetables." 

" No sooner does death occur than fungi grow. Tliese 
eat up, as it were, the soft decaying parts as fast as they 
rot ; and thus is inorganic matter converted into organic ; 
thus is death converted into life." 

Thus Mr. Smee, both by fact and argument, combats the 
idea that the fungi cause the disease. All this is in ac- 
cordance with our previous knowledge. He considers the 
disease to be caused by an insect. In support of this idea, 
he adduces many forcible arguments, and some important 
facts ; but he makes, after all, the following observation, 
which shows conclusiveh/ that the insect is not the cause ; 
and affords some countenance to the idea suggested m 
these pages. He says : " this creature cannot well live on 
a very vigorous plant, because it would be drowned by the 
water transpired at night. Hence it generally commences 
upon leaves which have in a great degree lost their vigor. 
On placing insects upon the new leaves of very vigorous 



40 THE REMEDY. 

plants, I have observed that the creature has alivays been 
obliged to leave them. It commences upon the larger and 
nearly exhausted leaves ; from these it passes to others, 
and so on till the entu*e foliage is affected." 

Again he says in another place, "we find that wild 
plants m general, and the assumed wild potato plant, re- 
sist much more effectively the ravages of the disease than the 
more highly cultivated varieties." 



THE REMEDY. 

Possibly in the great extent to which the epidemic has 
spread, it may not be so easy to apply the remedy with as 
complete success as might have been done at an earlier 
stage of its progress, before it had infected healthy sub- 
jects. If it were yet in that stage when its ravages were 
confined to the old subjects, and those already in a state 
of debility and partial decomposition, it would be su.ffi- 
cient to resort to seed, and suspend altogether the practice 
of raising from the tuber. This would give a young and 
healthy race of potatoes in the place of the feeble and 
sickly old stocks. Such a practice will even now probably 
be of great benefit, and if very generally followed, would re- 
duce the disease from an epidemic to a sporadic character. 
It may be, however, sufficient of itself to effect a cure. 
And this is the remedy which it was the writer's purpose 
to propose. Two auxiliaries -svill, however, be suggested, 
which it is thought, as they have been found advantageous 
in other diseases, may be in this also. The practice of 
planting the potato in the fall has been considered useful 
in England and in France. It was adopted in the begin- 
ning of this century in England, at the time when the 
disease known as the " cm! " was very prevalent. It has 



THE REMEDY. 41 

been lately recommended in France in a work published 
in Boulogne, in May, 1851, by M. Leroy Mabille, entitled, 
" Le Pomme de terre gueri par la plantation d' automne, 
et la cause de la malade expliquee par la guerison," as a 
cure for the epidemic under which the potato now suffers. 
The other auxiliary referred to is the application of salt. 
This has been used with effect as a preventive and cure of 
the mildew ; and if the disease in the potato is in part 
owing to fungus, though it may be one of a species differ- 
ing from the mildew, yet it may be reasonable to suppose 
that, if salt destroys the mildew, it may be fatal to other 
fungi of a species nearly allied. The mode in which salt 
has been used for this piu'pose was by sprmklmg with a 
water-pot, or laying on with a plasterer's brush, a solution 
in water of one pound to a gallon. I have not the book 
of M. Mabille, and do not know to what cause he attri- 
butes the disease. It is not obvious that any particular 
cause or form of disease should be satisfactorily proved or 
explained by the remedy applied in the practice of fall 
planting. I have more faith in the selection of new land, 
and in the application of salt and wood ashes, as a dress- 
ing, avoiding the use of stable matters, and by all means 
preventmg a contact of the seed and roots with such mat- 
ters. 

The application of copperas has been found very effec- 
tive in France as a restorative in curmg debilitated plants. 
This is applied in solution by watering, or by reducing it 
to powder and sowing it mixed with fine soil or earth. Its 
action has been very speedy and effectual, restoring the 
plant in a short time. It may be well as a remedy or 
restorative, in cases where healthy plants are attacked, to 
make use of salt or copperas. And the selection of new 
land, and fall plantmg may be recommended, the former 

especially, in connection with such remedies, or rather as 

4* 



42 THE REMEDY, 

preservatives of young tubers, not long from the seecl„ 
against the attacks of the disease. But these or any other 
appUcations or modes of culture, cannot give immortality 
to the plant. There is a time when, in spite of all human 
means and efforts, it must decay. To many of the varieties 
that have been long in cultivation, that time has come. 

If this be correct, the rot will continue to ravage the 
potato crop, notwithstanding all expedients that may be 
adopted, or whatever remedies may be applied, so long as 
those varieties are cultivated which have been a long time 
from the seed ; and though other remedies may be partially 
successful, the only effectual one is to be found in raising 
from the seed, or in cultivating those varieties which are 
but few years from the seed. Though this is the remedy, 
and the only one, yet it will not follow, however, that in 
every case of raising from seed, the plant will he free from 
disease. The seed may be from diseased potatoes, or there 
may be causes of disease arising to yoiuig, no less than to 
old subjects. As before said, disease may sometimes at- 
tack the child as well as the old man. No period of life, 
either animal or vegetable, is absolutely exempt from dis- 
ease. The conclusion, therefore, that the disease is not in 
consequence of old age, drawn merely from cases of sick- 
ness in yomig subjects, would be very illogical and erro- 
neous. 

It may be the case, however, that the long and tenacious 
adherence to the practice of raising from tubers has in- 
fected all the varieties in use with us to such an extent, 
either with actual disease, or with a morbid predisposition, 
that no healthy seed can be now obtained without resort- 
ing to the wild plant, in its original locality. Fourteen 
years has been assigned as the limit of duration for the 
varieties of the potato. Unless, therefore, we have some 
varieties derived from progenitors free from any taint or 



THE REMEDY. 



43 



any weakness predisposing them to disease, and the plant 
itself, the last in the line, from which the seed is to be 
furnished, is also in a healthy condition, very little may 
be gained by resorting to seed. The potato raised from 
new seed could then only be safe from the disease, when 
the seed was from a plant, itself not more than ten years 
from the seed, and each preceding renewal of the plant by 
seed, was, in like manner, the product of tubers from varie- 
ties not exceeding that age. It not being well authenti- 
cated that any seed of this kind can be obtained from any 
cultivated varieties now in use, it would consequently be 
impossible to speak confidently of the full success of re- 
production by seed obtained here. If it be, as supposed, 
deteriorated by the cause nam^ed, then the only remedy is 
in having recourse to the seed of the wild potato, or, what 
would be equally good, to tubers from them. 

Prof Mapes has raised a new variety from seed in New 
Jersey, which, I am informed, has not been infected with 
disease. And I have heard of others which have been 
exempt. 

The writer will repeat, and wishes it understood that he 
does not propose either the use of salt, or the adoption of 
fall planting, though partially they may be a preventive ; 
nor copperas, though a restorative in certain cases, as dis- 
tinct remedies for the prevailing epidemic. The remedy 
he proposes is reproduction: — raising new individuals 
from seed ; not extending their life by the planting of 
buds. The other practices are recommended as likely to 
aid in producing favorable conditions of the plant ; and 
preserving those not debilitated by age ; but the repro- 
duction by seed is alone relied on as giving to the potato 
an innate, fundamental health and \igor of constitution. 
There are other conditions also which it might be advan- 
tageous to attend to. The potato has become the subject 



44 THE REMEDY. 

of rather too much forcmg : — and fertilizers of the coarsest 
kind and the most stimulating and heating quality have 
been applied directly to the plant for a long succession 
of years. This practice is bad, not only as communicating 
an unpleasant savor to the potato ; an effect to which 
vegetables of a succulent kind are very susceptible, but 
undoubtedly tending to shorten the duration of vitality, 
and produce weakness in the plant. I would therefore 
suggest a discontinuance of this practice : and that a 
new soil should be chosen for a potato crop, with a fertil- 
izing only of salt and soot, or wood ashes ; or, if a rich 
mould, with no foreign fertilizer ; — and if a new soil 
cannot be had, that a first crop should intcr^'ene after the 
dressing has been put on the ground, or at least, if stable 
dressing is used, that it be as much as possible composted 
and mixed with the soil, and that all contact of it with the 
seed or root should be prevented. 

I desire intelligent farmers to attend to these conditions, 
and inform me of the results. 



The summary of the argument attempted in these 
pages, is : — 

First. We are taught equally by physiology, the 
nature and constitution of the vegetable world, and by the 
observation of all men, that plants have life, and must, 
and do have a period to that life. 

Secois'd. That the only mode of reproduction of new 
life in plants is by seeds ; — and the mode of multipUing 
by buds, is, like the growth of a branch, only a develop- 
ment of the bud ; and not a new life : — it is merely a 
multiplication of the form of .the old life. 

Third. That the period for the duration of the potato 
in vigor, is about fourteen years, and that many of the 



THE REMEDY. 45 

varieties now cultivated have been cultivated for that 
period ; and must be supposed therefore to have arrived 
at the limit of their vigor, at least, if not of their life : — 
and the potato raised last year from the tuber dates its life 
back to the time of beginning its variety by seed. 

Fourth. Analogy to the fruit trees, which are affected 
by canker ; — Avhich is the same disease now affecting the 
potato, so considered by the learned, called by Mr. C. W. 
Johnson, Knight, and Smee, the gangrene, — teaches that 
the condition of old age is that which causes the disease. 
Mr. Knight was satisfied of that point in regard to fruit 
trees ; and his opinion was the result of long observation 
and investigation : — and I consider it conclusive in rela- 
tion to the fruit trees. 

Fifth. It has long been ascertained that the fungi fix 
themselves on and draw nourishment from decaying vege- 
table matter: and rarely, if ever, on perfectly healthy 
plants. 

Sixth. It was ascertained by Mr. Smee that though 
the fungi were generally present on diseased potatoes, 
they did not appear till after the disease had com- 
menced. 

Seventh. Though Mr. Smee endeavors to prove that 
the aphis is the cause of the disease : — yet he confesses 
that when he placed these hisects on sound plants, they 
would not remain on them, but left them : — from which 
it must be considered that they do not cause the disease, 
but merely like the fungi, feed on diseased plants. 

Only two possible causes then remain. First; The 
disease must be an epidemic that indiscriminately attacks 
all plants, sound or weak, young or old : — or it must be, 
Second ; Old age. I hope I have succeeded in showing 
it must be the last, and nothing else. To some minds, 



46 THE REMEDY. 

it will api^ear, doubtless, that absolute certainty of the 
fact is not made out. It will be impossible, under any 
circumstances, to show a certainty, equal to that we have 
of the existence of the potato: but to my mind the 
reasoning here given is convincing. 



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